Relating Nanoparticle Properties to Biological Outcomes in Exposure Escalation Experiments

A fundamental goal in nano-toxicology is that of identifying particle physical and chemical properties, which are likely to explain biological hazard. The first line of screening for potentially adverse outcomes often consists of exposure escalation experiments, involving the exposure of micro-organisms or cell lines to a battery of nanomaterials. We discuss a modeling strategy, that relates the outcome of an exposure escalation experiment to nanoparticle properties. Our approach makes use of a hierarchical decision process, where we jointly identify particles that initiate adverse biological outcomes and explain the probability of this event in terms of the particle physico-chemical descriptors. The proposed inferential framework results in summaries that are easily interpretable as simple probability statements. We present the application of the proposed method to a data set on 24 metal oxides nanoparticles, characterized in relation to their electrical, crystal and dissolution properties

A Bayesian regression tree approach to identify the effect of nanoparticles properties on toxicity profiles

We introduce a Bayesian multiple regression tree model to characterize relationships between physico-chemical properties of nanoparticles and their in-vitro toxicity over multiple doses and times of exposure. Unlike conventional models that rely on data summaries, our model solves the low sample size issue and avoids arbitrary loss of information by combining all measurements from a general exposure experiment across doses, times of exposure, and replicates. The proposed technique integrates Bayesian trees for modeling threshold effects and interactions, and penalized B-splines for dose and time-response surfaces smoothing. The resulting posterior distribution is sampled via a Markov Chain Monte Carlo algorithm. This method allows for inference on a number of quantities of potential interest to substantive nanotoxicology, such as the importance of physico-chemical properties and their marginal effect on toxicity. We illustrate the application of our method to the analysis of a library of 24 nano metal oxides

Daily Preventive Zinc Supplementation Decreases Lymphocyte and Eosinophil Concentrations in Rural Laotian Children from Communities with a High Prevalence of Zinc Deficiency: Results of a Randomized Controlled Trial.

BACKGROUND:Zinc deficiency impairs immune function and is common among children in South-East Asia. OBJECTIVES:The effect of zinc supplementation on immune function in young Laotian children was investigated. METHODS:Children (n = 512) aged 6-23 mo received daily preventive zinc tablets (PZ; 7 mg Zn/d), daily multiple micronutrient powder (MNP; 10 mg Zn/d, 6 mg Fe/d, plus 13 other micronutrients), therapeutic dispersible zinc tablets only in association with diarrhea episodes (TZ; 20 mg Zn/d for 10 d after an episode), or daily placebo powder (control). These interventions continued for 9 mo. Cytokine production from whole blood cultures, the concentrations of T-cell populations, and a complete blood count with differential leukocyte count were measured at baseline and endline. Endline means were compared via ANCOVA, controlling for the baseline value of the outcome, child age and sex, district, month of enrollment, and baseline zinc status (below, or above or equal to, the median plasma zinc concentration). RESULTS:T-cell cytokines (IL-2, IFN-γ, IL-13, IL-17), LPS-stimulated cytokines (IL-1β, IL-6, TNF-α, and IL-10), and T-cell concentrations at endline did not differ between intervention groups, nor was there an interaction with baseline zinc status. However, mean ± SE endline lymphocyte concentrations were significantly lower in the PZ than in the control group (5018 ± 158 compared with 5640 ± 160 cells/μL, P = 0.032). Interactions with baseline zinc status were seen for eosinophils (Pixn = 0.0036), basophils (Pixn = 0.023), and monocytes (P = 0.086) but a significant subgroup difference was seen only for eosinophils, where concentrations were significantly lower in the PZ than in the control group among children with baseline plasma zinc concentrations below the overall median (524 ± 44 compared with 600 ± 41 cells/μL, P = 0.012). CONCLUSIONS:Zinc supplementation of rural Laotian children had no effect on cytokines or T-cell concentrations, although zinc supplementation affected lymphocyte and eosinophil concentrations. These cell subsets may be useful as indicators of response to zinc supplementation.This trial was registered at clinicaltrials.gov as NCT02428647

Reference to index of records of the Electrolytic-zinc Company Union rules

Rules of the Electrolytic Zinc Workers Union (1959), Employees' Medical Union (1963), Hobart Trades Hall Council (1957), Federated Iron Workers Association (1958), and membership card of Zinc Workers' Union issued to P. Taylor, patrolman (1963

Food Groups Associated with a Composite Measure of Probability of Adequate Intake of 11 Micronutrients in the Diets of Women in Urban Mali

The prevalence of micronutrient deficiency is high among women of reproductive age living in urban Mali. Despite this, there are little data on the dietary intake of micronutrients among women of reproductive age in Mali. This research tested the relationship between the quantity of intake of 21 possible food groups and estimated usual micronutrient (folate, vitamin B-12, calcium, riboflavin, niacin, vitamin A, iron, thiamin, vitamin B-6, vitamin C, and zinc) intakes and a composite measure of adequacy of 11 micronutrients [mean probability of adequacy (MPA)] based on the individual probability of adequacy (PA) for the 11 micronutrients. Food group and micronutrient intakes were calculated from 24-h recall data in an urban sample of Malian women. PA was lowest for folate, vitamin B-12, calcium, and riboflavin. The overall MPA for the composite measure of 11 micronutrients was 0.47 +/- 0.18. Grams of intake from the nuts/seeds, milk/yogurt, vitamin A-rich dark green leafy vegetables (DGLV), and vitamin C-rich vegetables food groups were correlated (Spearman's rho = 0.20-0.36; P 0.5, respectively. These findings can be used to further the development of indicators of dietary diversity and to improve micronutrient intakes of women of reproductive age. J. Nutr. 140: 2070S-2078S, 2010

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Operational Issues and Trends Associated with the Pilot Introduction of Zinc for Childhood Diarrhoea in Bougouni District, Mali

Zinc for the treatment of childhood diarrhoea was introduced in a pilot area in southern Mali to prepare for a cluster-randomized effectiveness study and to inform policies on how to best introduce and promote zinc at the community level. Dispersible zinc tablets in 14-tablet blister packs were provided through community health centres and drug kits managed by community health workers (CHWs) in two health zones in Bougouni district, Mali. Village meetings and individual counselling provided by CHWs and head nurses at health centres were the principal channels of communication. A combination of methods were employed to (a) detect problems in communication about the benefits of zinc and its mode of administration; (b) identify and resolve obstacles to implementation of zinc through existing health services; and (c) describe household-level constraints to the adoption of appropriate home-management practices for diarrhoea, including administration of both zinc and oral rehydration solution (ORS). Population-based household surveys with caretakers of children sick in the previous two weeks were carried out before and four months after the introduction of zinc supplementation. Household follow-up visits with children receiving zinc from the health centres and CHWs were conducted on day 3 and 14 after treatment for a subsample of children. A qualitative process evaluation also was conducted to investigate operational issues. Preliminary evidence from this study suggests that the introduction of zinc does not reduce the use of ORS and may reduce inappropriate antibiotic use for childhood diarrhoea. Financial access to treatments, management of concurrent diarrhoea and fever, and high use of unauthorized drug vendors were identified as factors affecting the effectiveness of the intervention in this setting. The introduction of zinc, if not appropriately integrated with other disease-control strategies, has the potential to decrease the appropriate presumptive treatment of childhood malaria in children with diarrhoea and fever in malaria-endemic areas

Operational Issues and Trends Associated with the Pilot Introduction of Zinc for Childhood Diarrhoea in Bougouni District, Mali

Zinc for the treatment of childhood diarrhoea was introduced in a pilot area in southern Mali to prepare for a cluster-randomized effectiveness study and to inform policies on how to best introduce and promote zinc at the community level. Dispersible zinc tablets in 14-tablet blister packs were provided through community health centres and drug kits managed by community health workers (CHWs) in two health zones in Bougouni district, Mali. Village meetings and individual counselling provided by CHWs and head nurses at health centres were the principal channels of communication. A combination of methods were employed to (a) detect problems in communication about the benefits of zinc and its mode of administration; (b) identify and resolve obstacles to implementation of zinc through existing health services; and (c) describe household-level constraints to the adoption of appropriate home-management practices for diarrhoea, including administration of both zinc and oral rehydration solution (ORS). Population-based household surveys with caretakers of children sick in the previous two weeks were carried out before and four months after the introduction of zinc supplementation. Household follow-up visits with children receiving zinc from the health centres and CHWs were conducted on day 3 and 14 after treatment for a subsample of children. A qualitative process evaluation also was conducted to investigate operational issues. Preliminary evidence from this study suggests that the introduction of zinc does not reduce the use of ORS and may reduce inappropriate antibiotic use for childhood diarrhoea. Financial access to treatments, management of concurrent diarrhoea and fever, and high use of unauthorized drug vendors were identified as factors affecting the effectiveness of the intervention in this setting. The introduction of zinc, if not appropriately integrated with other disease-control strategies, has the potential to decrease the appropriate presumptive treatment of childhood malaria in children with diarrhoea and fever in malaria-endemic areas